That both children and adults need a certain amount of fiber every day is indisputable. The sad truth is, despite years of public education and scores of clinical trials telling us we need more fiber in our diets, most of us are still failing in this area.
Even those of us who think we’re getting enough fiber in our diets are failing. According to the USDA, Americans consume foods rich in dietary fiber at below recommended levels (1).
Fiber has numerous health benefits, as it’s necessary for proper functioning of the body. It’s also important to eat a variety of dietary fibers so you get the full range of benefits.
What are the benefits of dietary fiber?
The benefits of eating enough fiber include reduction in risk of contracting the following diseases:
- heart disease
- diverticular disease
- type 2 Diabetes
In addition, it solves constipation woes for most people. It does not, however, have any real effect on the risk of getting colon cancer (2).
What is fiber?
Fiber can be either insoluble or soluble. The physical characteristics of insoluble fiber do not change when exposed to water.
Soluble fiber, on the other hand, will dissolve when immersed in water. Researchers are now finding that fiber’s health benefits are not directly related to whether or not it’s soluble, so these terms are used less and less (3).
But they still help you to understand what fiber is. Historically, the insoluble fibers were described as those providing bulk and weight to the stool. Now, however, it’s been discovered that some soluble fibers do the same thing.
Soluble fibers have traditionally been known as those which are broken down by bacteria in the large intestine. Examples of soluble fibers include oatmeal, blueberries, beans, nuts, and oatmeal.
Examples of insoluble fibers include things like whole wheat bread, tomatoes, brown rice, legumes, and carrots.
What are the sources of dietary fiber?
Dietary fiber is found in things like vegetables, fruit, whole grains, beans and peas, and nuts. Bran is an excellent source of fiber.
Some foods are enriched with fiber, but it’s unclear whether consuming these foods provides the same health benefits as consuming foods naturally rich in fiber (1).
Americans are definitely failing at getting enough fiber.
Some sad facts: Americans eat an average of 1.1 serving of fruit and 1.6 servings of vegetables per day (4). This is why consumption of dietary fiber is now a public health concern in the United States.
Add to that the fact that people ages 2 to 30 consume more than half their fruit intake in the form of juice, (1) and the picture looks even worse. Juice can be part of a healthy diet but it’s completely lacking in fiber.
- We consume only 15% of the recommended intake levels of whole grains.
- …and only 42% of the recommended intake for fruit
- …59% for vegetables
- …and 40% of the recommended intake for fiber (1).
Here’s how much fiber we need every day.
The USDA recommends 25 g of fiber per day for women and 38 g for men (1). With an average of only 15 g per day, we’re failing miserably.
Think you’re getting enough fiber? Check these common foods.
To get your 25 – 38 grams of fiber per day, you’ll have to work harder than you probably think. That wonderful apple you ate? Only 3 grams of fiber.
- 1/2 cup of canned kidney beans: 9.7 g
- lima beans: 5.8 g
- 1 tbsp of bran meal: 2 g
- 1/2 cup of raw broccoli: 4 g
- 1/4 cup of raw carrots: 1.7 g
- 1/2 cup of All-Bran cereal: 10.4 g
- 3/4 cup of oatmeal: 7.7 g
- 1/2 cup of swiss chard: 4 g
- 1 cup of lentils: 15.6 g
- 1 cup of boiled split peas: 16.3 g
- 1 cup of whole wheat macaroni: 5.7 g
Clearly, beans and legumes are some of the most fiber-rich foods we can eat. Artichokes are surprisingly high in fiber, as are raspberries.
Fiber helps with weight control.
Fiber improves satiety, which is what makes you feel full. It makes you feel full without adding extra calories, which is what does the trick as far as weight loss goes.
Fiber lowers the risk of heart disease.
Eating dietary fiber will lower your risk of coronary heart disease. An analysis of 10 cohort studies with follow-ups over 6 to 10 years in over 5200 men and women showed evidence that eating cereals and fruit high in fiber was associated with lower risk of coronary heart disease (7).
Fiber does this by lowering the blood cholesterol.
Lack of fiber can increase the risk of Type 2 Diabetes.
Fiber in the diet may also reduce the risk of type 2 Diabetes. A large-scale study performed in 1991 found that low-fiber diets were associated with increased risk of type 2 Diabetes (8). Over 91,000 women filled out a comprehensive questionnaire about their dietary intake. This info was updated in 1995.
Fiber lowers the risk of type 2 Diabetes by lowering the glycemic load of foods.
Fiber may decrease the incidence of diverticular disease.
Fiber may not improve your odds with colorectal cancer, but it may help ward off diverticular disease. A study found that insoluble fiber was associated with decreased risk of diverticular disease in men, from data gathered on almost 44,000 men (9).
Fiber solves the most common US gastrointestinal complaint.
Finally, did you know that the most common complaint of the GI tract is constipation? (10) If all the people complaining of this condition were to learn about the importance of fiber, there would be way fewer unhappy people in the world.
The final word.
Nobody would argue that dietary fiber is important. It bulks up the stool, lowers blood cholesterol, lowers the glycemic impact of the foods you eat, and makes you feel full longer.
It’s hard to actually get enough fiber in the diet, however, without actively seeking out sources of food rich in fiber.
Summary: Awareness of fiber content of the food you eat can go a long way towards your health in many ways.
All references retrieved 10/21/2015
- US Department of Agriculture, US Department of Health and Human Services. Dietary Guidelines for Americans. Retrieved from http://health.gov/dietaryguidelines/dga2010/DietaryGuidelines2010.pdf
- Fuchs CS et al. Dietary fiber and the risk of colorectal cancer and adenoma in women. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/9895396
- FiberFacts. Retrieved from http://fiberfacts.org/for-consumers/
- Collins, Sarah. The Average American Diet Statistics. Retrieved from http://healthyeating.sfgate.com/average-american-diet-statistics-10350.html
- Mount Sinai Health System Fiber Chart. Retrieved from https://www.wehealny.org/healthinfo/dietaryfiber/fibercontentchart.html
- Chart of high-fiber foods. The Mayo Clinic. Retrieved from http://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/high-fiber-foods/art-20050948
- Pereira MA et al. Dietary fiber and risk of coronary heart disease: a pooled analysis of cohort studies. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/14980987
- Schulze MB et al.Glycemic index, glycemic load, and dietary fiber intake and incidence of type 2 diabetes in younger and middle-aged women. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/15277155
- Aldoori WH et al. A prospective study of dietary fiber types and symptomatic diverticular disease in men. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/9521633
- Harvard T.H.Chan School of Public Health. Fiber. Retrieved from http://www.hsph.harvard.edu/nutritionsource/carbohydrates/fiber/